Extract Server configuration into a Configuration object

lib/action_cable/connection/base.rb

@@ -117,7 +117,7 @@ module ActionCable
         # Tags are declared in the server but computed in the connection. This allows us per-connection tailored tags.
         def new_tagged_logger
           TaggedLoggerProxy.new server.logger, 
-            tags: server.log_tags.map { |tag| tag.respond_to?(:call) ? tag.call(request) : tag.to_s.camelize }
+            tags: server.config.log_tags.map { |tag| tag.respond_to?(:call) ? tag.call(request) : tag.to_s.camelize }
         end
 
         def started_request_message

lib/action_cable/connection/subscriptions.rb

@@ -22,8 +22,8 @@ module ActionCable
         id_key = data['identifier']
         id_options = ActiveSupport::JSON.decode(id_key).with_indifferent_access
 
-        subscription_klass = connection.server.registered_channels.detect do |channel_klass|
-          channel_klass == id_options[:channel].safe_constantize
+        subscription_klass = connection.server.channel_classes.detect do |channel_class|
+          channel_class == id_options[:channel].safe_constantize
         end
 
         if subscription_klass

lib/action_cable/server.rb

@@ -3,6 +3,7 @@ module ActionCable
     autoload :Base, 'action_cable/server/base'
     autoload :Broadcasting, 'action_cable/server/broadcasting'
     autoload :Connections, 'action_cable/server/connections'
+    autoload :Configuration, 'action_cable/server/configuration'
     autoload :Worker, 'action_cable/server/worker'
   end
 end

lib/action_cable/server/base.rb

@@ -4,43 +4,26 @@ module ActionCable
       include ActionCable::Server::Broadcasting
       include ActionCable::Server::Connections
 
-      cattr_accessor(:logger, instance_reader: true) { Rails.logger }
+      cattr_accessor(:config, instance_accessor: true) { ActionCable::Server::Configuration.new }
+      
+      def self.logger; config.logger; end
+      delegate :logger, to: :config
 
-      attr_accessor :registered_channels, :redis_config, :log_tags
-
-      def initialize(redis_config:, channels:, worker_pool_size: 100, connection: Connection, log_tags: [ 'ActionCable' ])
-        @redis_config = redis_config.with_indifferent_access
-        @registered_channels = Set.new(channels)
-        @worker_pool_size = worker_pool_size
-        @connection_class = connection
-        @log_tags = log_tags
-
-        @connections = []
-
-        logger.info "[ActionCable] Initialized server (redis_config: #{@redis_config.inspect}, worker_pool_size: #{@worker_pool_size})"
+      def initialize
       end
 
       def call(env)
-        @connection_class.new(self, env).process
+        config.connection_class.new(self, env).process
       end
 
       def worker_pool
-        @worker_pool ||= ActionCable::Server::Worker.pool(size: @worker_pool_size)
+        @worker_pool ||= ActionCable::Server::Worker.pool(size: config.worker_pool_size)
       end
 
-      def pubsub
-        @pubsub ||= redis.pubsub
-      end
-
-      def redis
-        @redis ||= begin
-          redis = EM::Hiredis.connect(@redis_config[:url])
-          redis.on(:reconnect_failed) do
-            logger.info "[ActionCable] Redis reconnect failed."
-            # logger.info "[ActionCable] Redis reconnected. Closing all the open connections."
-            # @connections.map &:close
-          end
-          redis
+      def channel_classes
+        @channel_classes ||= begin
+          config.channel_paths.each { |channel_path| require channel_path }
+          config.channel_class_names.collect { |name| name.constantize }
         end
       end
 
@@ -48,10 +31,22 @@ module ActionCable
         @remote_connections ||= RemoteConnections.new(self)
       end
 
-      def connection_identifiers
-        @connection_class.identifiers
+      def pubsub
+        @pubsub ||= redis.pubsub
       end
 
+      def redis
+        @redis ||= EM::Hiredis.connect(config.redis[:url]).tap do |redis|
+          redis.on(:reconnect_failed) do
+            logger.info "[ActionCable] Redis reconnect failed."
+            # logger.info "[ActionCable] Redis reconnected. Closing all the open connections."
+            # @connections.map &:close
+          end            
+        end
+      end
+
+      def connection_identifiers
+        config.connection_class.identifiers
       end
     end
   end

lib/action_cable/server/broadcasting.rb

@@ -10,7 +10,7 @@ module ActionCable
       end
 
       def broadcasting_redis
-        @broadcasting_redis ||= Redis.new(redis_config)
+        @broadcasting_redis ||= Redis.new(config.redis)
       end      
 
       private

lib/action_cable/server/configuration.rb

@@ -0,0 +1,51 @@
+module ActionCable
+  module Server
+    class Configuration
+      attr_accessor :logger, :log_tags
+      attr_accessor :connection_class, :worker_pool_size
+      attr_accessor :redis_path, :channels_path
+
+      def initialize
+        @logger   = Rails.logger
+        @log_tags = []
+
+        @connection_class  = ApplicationCable::Connection
+        @worker_pool_size  = 100
+
+        @redis_path    = Rails.root.join('config/redis/cable.yml')
+        @channels_path = Rails.root.join('app/channels')
+      end
+
+      def channel_paths
+        @channels ||= Dir["#{channels_path}/**/*_channel.rb"]
+      end
+
+      def channel_class_names
+        @channel_class_names ||= channel_paths.collect do |channel_path|
+          Pathname.new(channel_path).basename.to_s.split('.').first.camelize
+        end
+      end
+
+      def redis
+        @redis ||= config_for(redis_path).with_indifferent_access
+      end
+
+      private
+        # FIXME: Extract this from Rails::Application in a way it can be used here.
+        def config_for(path)
+          if path.exist?
+            require "yaml"
+            require "erb"
+            (YAML.load(ERB.new(path.read).result) || {})[Rails.env] || {}
+          else
+            raise "Could not load configuration. No such file - #{path}"
+          end
+        rescue Psych::SyntaxError => e
+          raise "YAML syntax error occurred while parsing #{path}. " \
+            "Please note that YAML must be consistently indented using spaces. Tabs are not allowed. " \
+            "Error: #{e.message}"
+        end
+    end
+  end
+end
+

test/server_test.rb

@@ -17,7 +17,7 @@ class ServerTest < ActionCableTest
   end
 
   test "channel registration" do
-    assert_equal ChatServer.registered_channels, Set.new([ ChatChannel ])
+    assert_equal ChatServer.channel_classes, Set.new([ ChatChannel ])
   end
 
   test "subscribing to a channel with valid params" do